feat: Add comprehensive documentation suite and reorganize project structure

- Created complete documentation in docs/ directory
- Added PROJECT_OVERVIEW.md with feature highlights and getting started guide
- Added ARCHITECTURE.md with system design and technical details
- Added SECURITY.md with comprehensive security implementation guide
- Added DEVELOPMENT.md with development workflows and best practices
- Added DEPLOYMENT.md with production deployment instructions
- Added API.md with complete REST API documentation
- Added CONTRIBUTING.md with contribution guidelines
- Added CHANGELOG.md with version history and migration notes
- Reorganized all documentation files into docs/ directory for better organization
- Updated README.md with proper documentation links and quick navigation
- Enhanced project structure with professional documentation standards

android-icon-192x192.svg

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg width="192" height="192" viewBox="0 0 192 192" xmlns="http://www.w3.org/2000/svg">
+  <!-- Cloud -->
+  <g transform="translate(96, 48)">
+    <!-- Cloud body -->
+    <ellipse cx="0" cy="0" rx="56" ry="28" fill="#4A90E2"/>
+    <circle cx="-34" cy="-5" r="20" fill="#4A90E2"/>
+    <circle cx="34" cy="-5" r="20" fill="#4A90E2"/>
+    <circle cx="-17" cy="-17" r="13" fill="#4A90E2"/>
+    <circle cx="17" cy="-17" r="13" fill="#4A90E2"/>
+    
+    <!-- Cloud smile -->
+    <path d="M -17 5 Q 0 17 17 5" stroke="#FFFFFF" stroke-width="4.5" fill="none" stroke-linecap="round"/>
+    
+    <!-- Cloud eyes -->
+    <circle cx="-10" cy="-2" r="5" fill="#FFFFFF"/>
+    <circle cx="10" cy="-2" r="5" fill="#FFFFFF"/>
+    <circle cx="-10" cy="-2" r="2.5" fill="#333"/>
+    <circle cx="10" cy="-2" r="2.5" fill="#333"/>
+  </g>
+  
+  <!-- PC Monitor -->
+  <g transform="translate(96, 131)">
+    <!-- Monitor screen -->
+    <rect x="-48" y="-24" width="96" height="36" rx="3" fill="#2C3E50" stroke="#4A90E2" stroke-width="4"/>
+    <rect x="-42" y="-18" width="84" height="24" rx="1.5" fill="#34495E"/>
+    
+    <!-- Screen content -->
+    <rect x="-36" y="-15" width="12" height="3" fill="#4A90E2"/>
+    <rect x="-36" y="-10" width="18" height="1.5" fill="#7FB3D3"/>
+    <rect x="-14" y="-15" width="9" height="9" fill="#5DADE2"/>
+    <rect x="-3" y="-15" width="12" height="3" fill="#4A90E2"/>
+    
+    <!-- Monitor stand -->
+    <rect x="-6" y="12" width="12" height="18" fill="#34495E"/>
+    <rect x="-24" y="30" width="48" height="6" rx="1.5" fill="#2C3E50"/>
+  </g>
+</svg>